Hydrazine gel composition

ABSTRACT

Gelled fuel compositions comprising an amine fuel and a commercially available polymer containing mannose, glucose, potassium glucuronate and acetyl; also mixtures of the present gelled amine fuel and gelled petroleum fuels. These gelled fuels are mechanically stable at from -65* F to 165* F and have excellent suspending properties for solid particles which provide performance gains measured by burnt velocity.

United States atent [191 1111 3,821,043 Sippel [4 June 28, 1974 [5 HYDRAZINE GEL COMPOSITION 3,190,777 6/1965 Breza et a1 149/57 7 m1 Nathan 1 2,122,231 2/1222 2:212:52. 112/2222 [73] Assignee: The United States of America as represented by the Secretary of the Primary ExaminerBenjamin R. Padgett Navy, Washington, DC. Assistant Examiner-E. A. Miller Attorney, Agent, or FirmR. S. Sciascia; Roy Miller; [22] Filed. Sept. 2, 1966 Lloyd C. K Pohl [21] App]. No: 578,421

[57] ABSTRACT 149/36 L g Gelled fuel compositions comprising an amine fuel [58] d 18 57 22 and a commercially available polymer containing 9 0 e Tc 1 2 mannose, glucose, potassium glucuronate and acetyl; also mixtures of the present gelled amine fuel and gelled petroleum fuels. These gelled fuels are mechan- [56] References cued ically stable at from 65 F to 165 F and have excel- UNITED STATES PATENTS lent suspending properties for solid particles which 3,035,948 5/1962 Fox 149/19 provide performance gains measured by burnt veloc- 3,077,072 2/1963 Rice 149/36 ity 3,097,120 7/1963 Hoffman et a1 149/19 3,113,057 12/1963 Butcher 149/19 9 Claims, N0 Drawings HYDRAZINE GEL COMPOSITION The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalities thereon or therefor.

The present invention relates to propellant compositions and to the preparation thereof; more particularly to improved high performance gelled fuel compositions.

Those working on the development of improved propellant systems have used solid additives in liquid rocket fuels to provide performance gains measured by burnt velocity. The present invention provides a means for suspending solid particles in liquid fuels so that the composition can be used in a modified liquid system.

It is therefore an object of the invention to provide a composition with improved physical properties which can be used as a rocket propellant fuel.

Another object is to provide a propellant composition which is safe and easy to handle.

Yet another objectis to provide a gelled propellant composition which maintains its physical properties over a wide temperature range of 65 F. to 165 F. even after prolonged storage periods.

Other objects, features, and many of the attendant advantages of this invention will be readily appreciated as the same become better understood by reference to the detailed description.

In accordance with the present invention a small amount of a polymeric colloid sold under the tradename Kelzan was mixed into amine fuels, hydrazine, unsymmetrical dimethylhydrazine, monomethylhydrazine, and other hydrazine derivatives, and mixtures thereof. The product exhibits great cohesiveness and will pull into long thread-like strings when scooped up. It has excellent suspending properties for hard-tosuspend solids such as powdered metals including aluminum, zirconium, zirconium hydride, beryllium, titanium, uranium, tungsten and boron. Moderate viscosity changes may occur with temperature variation. The new gel composition is compatible with petroleum fuel gelled with polyisobutylene or napalm and kerosene gelled with carboxyterminated polybutadiene. I-Iydrazine and its derivatives are not miscible with petroleum fuels. However, it was discovered that the present new gel composition was compatible with gelled JP fuel, and gelled kerosene making this a great advance in the art which reduces the cost of the exotic fuels by mixing in less expensive fuel.

The gelling agent, Kelzan, used herein, is a polymer containing mannose, glucose, potassium glucuronate and acetyl in the approximate molar ratio of 221:1:1. It is prepared by bacterial synthesis using the bacterium Xanthomonas Campestris and dextrose as the media and is described in US. Pat. No. 3,067,038 which issued December 4, 1962.

The following examples are presented to illustrate the invention and should not be considered as limiting the scope thereof.

EXAMPLE l-Continued Percent by weight A mixture consisting of monomethylhydrazine and 14% hydrazine.

Due to the presence of carbon and the alkalinity of the fuel, it is necessary to start the gelling action by first adding all the gel to a small portion of the fuel having a reduced pH of approximately 7 8, which is accomplished by adding the acid to a small amount of the MHF-3. The polysaccharide dissolves and the swelling action starts. The remainder of the fuel is then slowly poured into the gel with constant stirring until half the required fuel has been poured in. The remaining half can be poured in all at once and mixed into the final gel.

The resulting gelled fuel was a thick rubbery type gel. Centrifuged for 25 minutes at 500 gs and 1,730 rpm, no syneresis was noticed. At -65 F. for A: hour only a small increase in viscosity resulted, but the gel could still be moved easily. When left in an oven at F. for 43 days, no mechanical change was noted.

EXAMPLE 11 Ingredients by wt Ml-IF-3 98.0 Adipic acid 1.0 Polysaccharide (Kelzan) 1.0

The mixing procedure described in Example I was followed. The gelled fuel exhibited the same physical properties as that prepared in Example 1.

EXAMPLE III Ingredients of wt MI-IF-3 18.0 Glacial acetic acid 1.0 Polysaccharide (Kelzan) 1.0 Aluminum, 5p. 80.0

The ingredients were blended together as described in Example I. A sample which was centrifuged for 25 minutes at 500 gs and 1730 rpm showed only a trace of gel separation. At -65 F. for 30 minutes a moderate increase in viscosity was observed.

EXAMPLE IV Ingredients by wt MGGP-l 99. Polysaccharide (Kelzan) 1.

'MGGP-l consists of 27% water, 10% hydrazine nitrate and 63% hydrazine.

EXAMPLE V lngredients by wt *MHF-S 95.0 Kelzan 5.0

'MHF-S consists of 19% hydrazine nitrate.

26% hydrazine and 55% monomethylhydrazine.

The product was a thick rubbery type gel which showed no noticeable change at 140 F.

BAP-1185 is another amine fuel mixture consisting of 29.8 percent hydrazine, 50.5 percent monomethylhydrazine and 19.7 percent water which gels success- This product when centrifuged showed no syneresis and little viscosity change at temperatures varying from 65 F. to 165 F.

Fuels which require an acidifying agent such as adipic acid to dissolve the Kelzan and start the gelling action include Ml-lF-3 (defined herein), monomethyl hydrazine, Aerozine (50 percent unsymmetrical dimethylhydrazine and 50 percent hydrazine) and unsymmetrical dimethylhydrazine. The fuels used in Examples IV, V, and V1 do not require an acidifying agent to start the Kelzan gelling action.

it was also discovered that when Kelzan was used with other gelling agents a reduction in the total amount of gelling agent resulted as set out in the following examples in which hydroxyethylcellulose (HEC) and silicon dioxide sold under tradename of Cab-O-Sil had been used.

EXAMPLE VII Formulation A Formulation B Formulation B (not using Kelzan) was prepared by gelling the Ml-IF-3 with the required amount of silicon dioxide and allowed to stand overnight to allow the mixture to gas off. The next day the premixed solids, HEC and aluminum were added to the gel and mixed for 1 to 2 hours at 80 rpm.

Formulation A (using Kelzan) was prepared by gel ling the Ml-lF-3 first. To the required amount of Kelzan was added an amount of MHF-3 equal to approximately times the weight of Kelzan and thoroughly stirred. The adipic acid powder was then added and the mixture stirred until the gel formed. More Ml-lF-3 was slowly stirred into the gel until one-third of the required amount of Ml-lF-3 has been added. The gel was allowed to stand overnight and the remainder of the MHF-3 was added in the morning. The gel was now ready for the mixer which contained a properly weighed amount of premixed aluminum and hydroxyethylcellulose powder. The mixing of the gelled slurry was completed in from 1 to 2 hours at rpm.

Neither formulations A nor B when centrifuged for 30 minutes at 500 gs and 1730 rpm exhibited syneresis.

Two more comparisons were made with similar results showing that there is a reduction in the amount of gelling agents required when using Kelzan. They were prepared in quantity size of less than k pint as follows:

Formulation C Formulation D Ingredients by wt Ingredients by wt Zirconium, 20y. 70.0 Zirconium. 20;; 70.0 Silicon dioxide 0.4 HEC 0.6 MHF-3 28.6 MHF-3 27.15 Kelzan 0.8 Silicon dioxide 2.25

.Adipic acid 0.2

Total gelling Total gelling agents 1.4 agents 2.85 Formulation E Formulation F lngredients by wt lngredients by wt Aluminum, 5p. 60.0 Aluminum, Sp. 60.0 MHF-3 37.7 MHF-3 36.2 Kelzan 1.9 HEC 0.8 Adipic acid 0.3 Silicon dioxide 3.0 Silicon dioxide 1.0

Total gelling Total gelling agent 2.3 agent 3.8

The addition of liquids containing hydrocarbons or silicone oils increase the thermal stability of the new gelled amine fuels when subjected to a constant elevated temperature of F. or above. This is illustrated in Example V111 with silicone oil DC 200 which is dimethylpolysiloxane.

EXAMPLE Vlll This formulation shows excellent suspending properties for aluminum.

The formulations disclosed herein particularly illustrate Kelzan as an excellent gelling agent for fuels containing amines. Gels formed with Kelzan exhibit greater cohesiveness than those gelled with hydroxyethylcellulose (I-IEC) or silicon dioxide (Cab-O-Sil) which can be scooped up in globs. Some of the Kelzan-gelled fuel formulation will pull long thread-like strings when scooped out. The Kelzan-gelled fuelshave demonstrated an excellent suspending property for hard to suspend solids (such as aluminum powder). The viscosity shows very little change with temperature variation as low as 65 F. and up to 165 F. Formulations with Kelzan are made which can be poured readily and appear thinner than other gels, yet particles can be kept in suspension. The gelled fuel consistency can be varied to range from a pourable, thin type gel to a rubber-like material requiring an external force to make it flow.

It was also discovered that with gelled fuels it is possible to obtain homogeneous mixtures of fuels which in the liquid state are not normally miscible with each other. The procedure is to gel the individual fuels separately with suitable gelling agents and then mix the gels into a homogeneous gelled mixture. To obtain the best mixtures it was found that addition of a third gelling agent such as silicon dioxide or a stearate acted similar to a cross-linking agent to combine two dissimilar gels. Thus, it is possible to combine immiscible liquids to form new homogeneous gelled fuel mixtures with improved physical properties and combustion characteristics which the individual gels do not have. Such improved gels also represent a considerable cost saving. A cheap gelled hydrocarbon fuel can be used as an extender for expensive gelled hydrazine or hydrazine type mixtures. The following are examples of the homogeneous mixtures of fuels wherein the new Kelzan-gelled fuel formulation is used as a component.

EXAMPLE X A 50/50 weight percent JP-S fuel gelled with 4 percent napalm was added to hydrazine gelled with 1.3 percent Kelzan. The formulation is as follows:

Ingredients by wt JP-5 46.2 Napalm M2 1.9 Hydrazine 47.5 Kelzan 0.6 Aluminum palmitate 2.4 Silicon dioxide 1.4

EXAMPLE XI A 50/50 weight percent of J P-5 fuel gelled with 2 percent polyisobutylene was mixed with hydrazine gelled with 4 percent Kelzan. The formulation is as follows:

Ingredients 72 by wt .IP-5 Polyisobutylene Hydrazine Kelzan Aluminum palmitate Silicon dioxide The JP-5 fuel was mixed with the polyisobutylene to form agel and the hydrazine was gelled with the Kelzan, then the two gel mixtures were blended together with the addition of the aluminum palmitate and silicon dioxide. The product was of a jello-like consistency. When centrifuged for 30 minutes at 500 gs and 1730 rpm no syneresis was observed.

EXAMPLE XII A 50/50 weight percent of JP-5 fuel gelled with 4 percent polyisobutylene was mixed with MHF-S gelled with 1 percent Kelzan. The formulation follows:

Ingredients by wt JP-S 47.1 Polyisobutylene 2.0 MHF-S 48.5 Kelzan 0.5 Aluminum palmitate 2.0

No syneresis was observed when this product was centrifuged for 30 minutes at 500 gs and 1,730 rpm.

EXAMPLE XIII Ingredients by wt Gasoline 43.9

Carboxyterminated polybutadiene 4.9

MHF-S 48.3

Kelzan 0.5

Aluminum palmitate 2.4

EXAMPLE XIV Ingredients Aluminum. 5 3 MHF-3 2 Silicon dioxide I-IEC JP-S fuel 2 Napalm M2 Silicon dioxide EXAMPLE XV A 50/50 weight percent of JP- gelled with 4 percent napalm and MHF-3 gelled with 2 percent HEC were blended together.

Ingredients by wt Ml-lF-3 46.7 HEC 1.0 JP-S 45.7 Napalm M2 1.9 Silicon dioxide 4.7

JP-5 fuel a kerosene petroleum product was used most often in the examples because of its availability.

Napalm type Ml contains aluminum soaps of coconut oil acid, 50 percent; naphthenic acid, 25 percent; oleic acid 25 percent. Napalm, type M2, contains 95 percent of type Ml plus devolitilized silica aerogel (or other antiagglomerate) with a moisture content of 0.4 to 1 percent.

The use of Kelzan as a gelling agent for the amine fuels has several advantages: (1) it can be easily added directly to the liquid fuel without forming lumps; (2) it can be formulated into nonadhesive gels; and (3) it produces a gel with slightly lower viscosities.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A gelled high energy fuel composition mechanically stable at temperatures ranging from 65 F. to 165 F. comprising an amine fuel selected from the group consisting of hydrazine, hydrazine derivatives and mixtures thereof, and an effective amount up to about 5 percent by weight of a gelling agent which is a polymer containing m-annose, glucose, potassium glucuronate and acetyl in approximate ratio of 2:l:l:l.

2. The composition according to claim 1 in which the fuel is hydrazine.

3. The composition according to claim 1 in which the fuel consists of 86 percent by weight monomethylhydrazine and 14 percent hydrazine.

4. The composition according to claim 1 in which the fuel consists of 19 percent hydrazine nitrate, 26 percent hydrazine and 55 percent monomethylhydrazine.

S. A method for the preparation of the composition according to claim 1 which comprises 1. acidifying a small portion of said fuel 2. adding said agent to the acidified fuel to form a gel,

then

3. stirring into the gel the remainder of said fuel.

6. A gelled high energy fuel composition mechani cally stable at temperatures ranging from 65 F. to 165 F. comprising up to 20 percent by weight of a fuel selected from the group consisting of hydrazine, hydrazine derivatives and mixtures thereof,

an effective amount up to about 5 percent by weight gelling agent which is a polymer containing mannose, glucose, potassium flucuronate and acetyl in approximate ratio of 2:l:l:l, and

up to percent by weight of a member selected from the group consisting of aluminum, zirconium, magnesium, beryllium, titanium, uranium, zirconium hydride, tungsten and boron.

7. The composition according to claim 6 in which the fuel consists of 86 percent by weight monomethylhydrazine and 14 percent hydrazine and the metal consists of aluminum.

8. A gelled high energy mechanically stable fuel composition comprising a mixture of a gelled amine fuel and a gelled petroleum fuel said gelled amine fuel comprising an amine fuel selected from the group consisting of hydrazine, hydrazine derivatives, and mixtures thereof and an effective amount up to 5 percent by weight of a gelling agent selected from the group consisting of hydroxyethylcellulose, silicon dioxide, carboxyterminated polybutadiene, polyisobutylene, and a polymer composed of mannose, glucose, potassium glucuronate, and acetyl in an approximate ratio of 2:l:l:l, and mixtures thereof,

and said gelled petroleum fuel selected from a group consisting of gasoline and kerosene and an effective amount up to 10 percent of a gelling agent selected from the group consisting of polyisobutylene, carboxyterminated polybutadiene, aluminum palmitate, aluminum stearate, zinc stearate, and a mixture composed of 50 percent aluminum soaps of coconut oil acid, 25 percent naphthenic acid and 25 percent oleic acid.

9. The method for preparing the composition of claim 8 which comprises preparing the gelled amine fuel and gelled petroleum fuel in separate containers, then blending the two gelled fuels together until a homogeneous mixture results. 

2. The composition according to claim 1 in which the fuel is hydrazine.
 2. adding said agent to the acidified fuel to form a gel, then
 3. stirring into the gel the remainder of said fuel.
 3. The composition according to claim 1 in which the fuel consists of 86 percent by weight monomethylhydrazine and 14 percent hydrazine.
 4. The composition according to claim 1 in which the fuel consists of 19 percent hydrazine nitrate, 26 percent hydrazine and 55 percent monomethylhydrazine.
 5. A method for the preparation of the composition according to claim 1 which comprises
 6. A gelled high energy fuel composition mechanically stable at temperatures ranging from -65* F. to 165* F. comprising up to 20 percent by weight of a fuel selected from the group consisting of hydrazine, hydrazine derivatives and mixtures thereof, an effective amount up to about 5 percent by weight gelling agent which is a polymer containing mannose, glucose, potassium flucuronate and acetyl in approximate ratio of 2:1:1:1, and up to 80 percent by weight of a member selected from the group consisting of aluminum, zirconium, magnesium, beryllium, titanium, uranium, zirconium hydride, tungsten and boron.
 7. The composition according to claim 6 in which the fuel consists of 86 percent by weight monomethylhydrazine and 14 percent hydrazine and the metal consists of aluminum.
 8. A gelled high energy mechanically stable fuel composition comprising a mixture of a gelled amine fuel and a gelled petroleum fuel said gelled amine fuel comprising an amine fuel selected from the group consisting of hydrazine, hydrazine derivatives, and mixtures thereof and an effective amount up to 5 percent by weight of a gelling agent selected from the group consisting of hydroxyethylcellulose, silicon dioxide, carboxyterminated polybutadiene, polyisobutylene, and a polymer composed of mannose, glucose, potassium glucuronate, and acetyl in an approximate ratio of 2:1:1:1, and mixtures thereof, and said gelled petroleum fuel selected from a group consisting of gasoline and kerosene and an effective amount up to 10 percent of a gelling agent selected from the group consisting of polyisobutylene, carboxyterminated polybutadiene, aluminum palmitate, aluminum stearate, zinc stearate, and a mixture composed of 50 percent aluminum soaps of coconut oil acid, 25 percent naphthenic acid and 25 percent oleic acid.
 9. The method for preparing the composition of claim 8 which comprises preparing the gelled amine fuel and gelled petroleum fuel in separate containers, then blending the two gelled fuels together until a homogeneous mixture results. 